Lakes bathymetry is a line feature-based layer that includes bathymetric information for selected reservoirs, lakes, and ponds in Montana. The layer is based on information collected by multiple sources including contractors with Montana Department of Environmental Quality, the Bureau of Reclamation, and Montana Fish, Wildlife & Parks. Data collection methods vary over time with techniques using a variety of different equipment including manual and electronic depth soundings, use of a GPS receiver, and digitizing previously published bathymetry maps. Data were compiled at a variety of scales and resolutions, depending on the collection method used for a particular waterbody. These data are planned to be regularly updated, however bathymetry information for addtional waterbodies may become available and included in this layer as new information is collected and compiled.

Purpose:

Shorelines, islands and contours are shown for lakes, ponds, and reservoirs. Most data were generated using depth and location data collected in the field.

Time period of content:

Calendar date: 09/10/2015

Currentness reference: publication date

Status:

Progress: In work

Maintenance and update frequency: Irregular

Access constraints: None

Use constraints:

Users must assume responsibility to determine the usability of this data for their purposes. This data set is provided "as is" without warranty of any kind. Montana Fish, Wildlife & Parks (FWP) makes no representations or warranties whatsoever with respect to the accuracy or completeness of this data set and assumes no responsibility for the suitability of this data set for a particular purpose. FWP will not be liable for any damages incurred as a result of errors in this data set.

Data were derived from a variety of sources including: 1. CAD files that were georeferenced in ArcGIS (v 9.2) to the 2005 color aerial photography available through the Natural Resource Information System at http://nris.mt.gov/nsdi/orthophotos/naip_2005.asp and then converted to ESRI shapefile format. 2. Pre-existing image files that were georeferenced from which lines were digitized on screen. 3. GPS depth and locations from which Triangulated Irregular Network (TIN) data were generated using ArcGIS. 4. Manual depth soundings. 5. Pre-existing shapefiles or feature classes sent to or shared with FWP by other cooperating agencies.